Marsilio Fountaine is a Parisian astrologer and occultist, born in 1620, who invoked an infernal Duke to save Jeanne Devossie at Chambois.
History
Younger son of the bookseller Pier Fountaine and Adeline, daughter of a German printer, he grew up among books banned by the Church, read from age five and preferred the forbidden ones. Orphaned by dysentery in 1630, he was raised by his elder brother Phillipe, a painter. After the early death of Phillipe’s bookish, combative wife Marinette, Phillipe’s paintings darkened and stopped selling, and Marsilio lived by astrology and the occult.
Through the merchant Alphonse, his supplier, and a job involving a tax collector, he met Jeanne and Madeline Boulet. Under threat of a witchcraft charge, the royal authorities made him investigate a diabolical pact among nobles of southern France. The Felón brothers, lords of Chambois, meant to summon a demon with Jeanne as offering; to save her he invoked the Duke Murmur, with consequences not yet recorded.